Does *not* add a new entry if one doesn't exits, to counter the fact
that dialect.defs.IRCEvent.Type.NICK events don't belong to a channel,
and as such can't be regulated with ChannelPolicy
annotations. This way the user will only be moved if it was already added elsewhere.
Else we'll leak users.
Removes the old entry after assigning it to the new key.
Upon someone changing nickname, update their entry in the IRCPluginState.users
associative array to point to the new nickname.
Does *not* add a new entry if one doesn't exits, to counter the fact that dialect.defs.IRCEvent.Type.NICK events don't belong to a channel, and as such can't be regulated with ChannelPolicy annotations. This way the user will only be moved if it was already added elsewhere. Else we'll leak users.
Removes the old entry after assigning it to the new key.